CN109908497A - Calibrating coordinates device, system, method and medium - Google Patents
Calibrating coordinates device, system, method and medium Download PDFInfo
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- CN109908497A CN109908497A CN201910256465.6A CN201910256465A CN109908497A CN 109908497 A CN109908497 A CN 109908497A CN 201910256465 A CN201910256465 A CN 201910256465A CN 109908497 A CN109908497 A CN 109908497A
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Abstract
The embodiment of the invention discloses a kind of calibrating coordinates device, system, method and medium, which includes: the calibration point group of ontology and corresponding each imaging device；Calibration point group is arranged on the body, and each calibration point group includes at least a calibration point of the scanning range positioned at corresponding imaging device, and the spatial relation of the calibration point between different calibration point groups is fixed.Solve the problems, such as that the prior art can not accurately detect the coordinate transformation relation between positioning CT and the equal centers for guiding CT, to improve the accuracy of the Spot detections such as the two.
Description
Technical field
The present embodiments relate to technical field of medical equipment more particularly to a kind of calibrating coordinates device, system, method and
Medium.
Background technique
Integrated radiotherapy system generally comprise a positioning CT (Computed Tomography, computer tomography,
Abbreviation CT) 11 and a RT (Radiation Therapy, radiotherapy, abbreviation RT) 121, it is shown in Figure 1.Usual situation
Under, positioning CT 11 and RT 121 share a therapeutic bed 13, and RT is set to towards in the CT rack of 13 side of therapeutic bed.For
Termed image-guided radiotherapy convenient to carry out is additionally provided with the detection plate 122 towards RT 121 in the rack of positioning CT 11, from
And it is configured to the guidance CT 12 of rotary scanning.
In order to improve the accuracy of radiotherapy, need periodically to positioning CT coordinate and guide the consistency of CT (or RT) coordinate into
Row detection.The prior art is detected frequently with laser assisted, specifically: z-axis is parallel in the rack rotation center erection of positioning CT
The laser lamp 011 of transmitting, and plate 012 is disposed in the fixation position of the side RT, it is detected in rotation of positioning CT etc. by projection
The heart falls within (x, y) coordinate of plate 012 known to RT, to calculate positioning CT and guide the relative coordinate between CT.Current
In use environment, there are biggish limitations for such method, firstly, the installation of laser lamp 011 is difficult to ensure that laser beam absolutely hangs down
Directly in the x-y plane of RT；Secondly, the Plane of rotation of RT system and CT commonly use diameter 1mm laser beam distance herein apart more than 2m
Under be difficult to ensure focusing, keep its spot diameter excessive, reduce detection accuracy；Finally, this method is unable to measure out the two in the direction z
On equal centers between relationship, therefore in actual use, value conventional machinery installation guarantees that error is larger.
To sum up, the prior art can not accurately detect the coordinate relationship between positioning CT and the equal centers for guiding CT, need
A kind of calibrating coordinates device is provided, the coordinate conversion matrix between positioning CT and RT is detected by the device, and being based on should
The spatial relationship of both coordinate conversion matrix adjustment, to guarantee the consistency of the two coordinate.
Summary of the invention
The embodiment of the invention provides a kind of calibrating coordinates device, system, method and media, can not to solve the prior art
The problem of accurately detecting the coordinate relationship between positioning CT and the equal centers for guiding CT, to improve the Spot detections such as the two
Accuracy.
In a first aspect, the embodiment of the invention provides a kind of calibrating coordinates devices, between at least two imaging devices
The calibration of coordinate, comprising:
Ontology；
The calibration point group of corresponding each imaging device, is arranged on the body, and each calibration point group, which includes at least, to be located at
One calibration point of the scanning range of corresponding imaging device, and the spatial relation of the calibration point between different calibration point groups
It is fixed.
Second aspect, the embodiment of the invention also provides a kind of calibrating coordinates systems, based on coordinate described in first aspect
Calibrating installation, comprising:
Module is obtained, for obtaining partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated
Image, and the image of each imaging device includes the location information of the target alignment point calculated as coordinate；
Output module, for the spatial position between the location information and target alignment point according to the target alignment point
Relationship determines the coordinate conversion matrix between the imaging device.
The third aspect, the embodiment of the invention also provides a kind of coordinate calibration methods, with coordinate school described in first aspect
Standard apparatus is used cooperatively, comprising:
Obtain the image of partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and each institute
The image for stating imaging device includes the location information of the target alignment point calculated as coordinate；
According to the spatial relation between the location information and target alignment point of the target alignment point, determine described in
Coordinate conversion matrix between imaging device.
Fourth aspect, the embodiment of the invention also provides a kind of coordinate calibration methods, with coordinate school described in first aspect
Standard apparatus is used cooperatively, comprising:
Pendulum position is carried out to calibrating coordinates device, make the lubber-line while appearing in the scanning model of imaging device to be calibrated
In enclosing, and at least corresponding target alignment point calculated for coordinate of the scanning range of each imaging device；
Obtain the image of partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and each institute
The image for stating imaging device includes the location information of the target alignment point calculated as coordinate；
According to the spatial relation between the location information and target alignment point of the target alignment point, determine described in
Coordinate conversion matrix between imaging device.
5th aspect, it is described the embodiment of the invention also provides a kind of storage medium comprising computer executable instructions
Computer executable instructions as computer processor when being executed for realizing the coordinate calibration method as described in the third aspect.
The technical solution of calibrating coordinates device provided in an embodiment of the present invention, including ontology, and be set to corresponding on ontology
In the calibration point group of each imaging device, each calibration point group includes at least one of the scanning range positioned at corresponding imaging device
A calibration point, and the spatial relation of the calibration point between different calibration point groups is fixed, to make each imaging device to it
When partial coordinates calibrating installation in scanning range carries out image scanning, the spatial position of the calibration point between different calibration point groups
Relationship is constant, then can be according to the target alignment point calculated for coordinate in real space positional relationship and position in the picture
Confidence breath, determines the coordinate conversion matrix between imaging device, and the apparatus structure is simple, it is easy to accomplish.
Detailed description of the invention
To describe the technical solutions in the embodiments of the present invention more clearly, make required in being described below to embodiment
Attached drawing does one and simply introduces, it should be apparent that, drawings in the following description are some embodiments of the invention, for this
For the those of ordinary skill of field, without creative efforts, it can also be obtained according to these attached drawings others
Attached drawing.
Fig. 1 is the structural schematic diagram for the integrated radiotherapy system that background of invention provides；
Fig. 2A is the structural schematic diagram for the calibrating coordinates device that the embodiment of the present invention one provides；
Fig. 2 B is the structural schematic diagram for the another calibrating coordinates device that the embodiment of the present invention one provides；
Fig. 2 C is the structural schematic diagram for the another calibrating coordinates device that the embodiment of the present invention one provides；
Fig. 2 D is the schematic diagram of the partial coordinates calibrating installation for the positioning CT shooting that the embodiment of the present invention one provides；
Fig. 2 E is the schematic diagram of the partial coordinates calibrating installation for the guidance CT shooting that the embodiment of the present invention one provides；
Fig. 3 is the block diagram representation of calibrating coordinates system provided by Embodiment 2 of the present invention；
Fig. 4 is the another schematic diagram of calibrating coordinates system provided by Embodiment 2 of the present invention；
Fig. 5 is the flow chart for the coordinate calibration method that the embodiment of the present invention three provides；
Fig. 6 is the flow chart for the coordinate calibration method that the embodiment of the present invention four provides.
Specific embodiment
To make the object, technical solutions and advantages of the present invention clearer, hereinafter with reference to attached in the embodiment of the present invention
Figure, clearly and completely describes technical solution of the present invention by embodiment, it is clear that described embodiment is the present invention one
Section Example, instead of all the embodiments.Based on the embodiments of the present invention, those of ordinary skill in the art are not doing
Every other embodiment obtained under the premise of creative work out, shall fall within the protection scope of the present invention.
Embodiment one
The embodiment of the present invention has mentioned a kind of calibrating coordinates device.The coordinate that the device can be used between at least two imaging devices
Calibration, as shown in Fig. 2A, 2B and 2C, the calibration point group including ontology 21 and corresponding each imaging device, wherein calibration point group
It is set on ontology 21, each calibration point group includes at least a calibration point of the scanning range positioned at corresponding imaging device
22, and the spatial relation of the calibration point 22 between different calibration point groups is fixed.
Wherein, the imaging device of the present embodiment is usually radiation imaging apparatus, such as x-ray imaging equipment, the present embodiment
It is illustrated by taking positioning CT and guidance CT in integrated radiotherapy system (referring to Fig. 1) as an example.Since CT institute is usually at image
The plain film of three-dimensional CT image or a certain plane, and can be determined by the plain film of two orthogonal planes of calibrating coordinates device
The spatial relation of calibration point in calibrating coordinates device, therefore image described in the present embodiment is swept by each imaging device
The three-dimensional CT image for the partial coordinates calibrating installation retouched or the plain film of at least two orthogonal planes.Wherein, the plain film of the present embodiment
Be instigate CT equipment only moved along z-axis acquisition calibrating coordinates device two dimensional image, for example CT bulb is maintained at 0 degree of position,
And therapeutic bed only obtains calibrating coordinates device in the image of x-z-plane along z-axis moving sweep, CT bulb is maintained at 90 degree or 270
Spend position, and the calibrating coordinates device that only obtains along z-axis moving sweep of therapeutic bed is in the image of y-z plane.For another example, for cone
Pencil of forms CT, plain film refer to the calibrating coordinates device scanned when CT bulb is located at 0 degree of position and 90 degree of (or 270 degree) positions
In the image of x-z-plane and y-z plane.
In order to improve the accuracy of the calibrating coordinates between imaging device, the present embodiment further includes being used to support and fixing ontology
21 fixed frame 23 so that ontology 21 during image scanning will not deformation occurs, to guarantee between different calibration point groups
The spatial relation of calibration point opposite change will not occur.In some embodiments, fixed frame 23 be not limited to Fig. 2A, 2B and
Shape shown in 2C, as long as it can stablize support ontology 21.For example, due to imaging device be generally configured with pedestal and/or
The components such as rack, in order to enable the pedestal and/or rack of fixed frame 23 and imaging device do not generate interference, fixed frame 23 can be only
Two ends for supporting ontology 21, to avoid the pedestal and/or rack of imaging device.
Wherein, ontology is preferably made from a rigid material, rigid material can simply and easily keep different calibration point groups it
Between the spatial relation of calibration point fix；Certainly, ontology can also be fabricated from a flexible material, as long as fixed frame 23 can be protected
The spatial relation held between the calibration point of different calibration point groups is constant.
Preferably, the calibration point of different calibration point groups linearly arranges (A and Fig. 2 B referring to fig. 2), to simplify calibrating coordinates
Spatial relation between point, to reduce true according to the spatial relation of the calibration points of different calibration point groups in the picture
Determine the operand of the coordinate conversion matrix between imaging device.
In order to arrange the calibration point of different calibration point groups linearly, the calibration point of the present embodiment difference calibration point group can be with
It is set on the same characteristic curve of ontology (A and Fig. 2 C referring to fig. 2), or is set on same tag line (B referring to fig. 2), and should
Tag line is located on the inside or surface of ontology.Wherein, characteristic curve is that sideline or axial line of ontology etc. carry ontology itself spy
The line of reference breath, tag line can be to be set to intrinsic any bar line.Optionally, tag line is logical to the attenuation coefficient of ray
It is often different from attenuation coefficient of the ontology to ray, so as to show tag line on the image.
It is understood that passing through the calibration point in image if each calibration point group includes multiple calibration points
Location information when determining the coordinate conversion matrix between imaging device, it is thus necessary to determine that the target alignment point calculated for coordinate
Corresponding relationship.For the ease of the determination of the corresponding relationship, the shape (ginseng of each calibration point 22 in the calibration point group of the present embodiment
See Fig. 2 B) or it is different to the attenuation coefficient of ray, so that the shape or gray value difference of calibration point on the image, so as to root
The target alignment point calculated in different calibration point groups for coordinate is determined according to calibration point shape on the image or gray value.
In the present embodiment, calibration point 22 is made of from ontology 21 different materials, so that calibration point 22 can be in correspondence
Imaging device scanning obtain image in be identified.For example, calibration point 22 and ontology 21 are right for radiation imaging apparatus
The decaying of ray is different.Optionally, calibration point 22 can be the metal ball being set in ontology 21 or calibration point 22 can be shape
At the hole in ontology 21.
The technical solution of calibrating coordinates device provided in an embodiment of the present invention, including ontology, and be set to corresponding on ontology
In the calibration point group of each imaging device, each calibration point group includes at least one of the scanning range positioned at corresponding imaging device
A calibration point, and the spatial relation of the calibration point between different calibration point groups is fixed, to make each imaging device to it
When partial coordinates calibrating installation in scanning range carries out image scanning, the spatial position of the calibration point between different calibration point groups
Relationship is constant, then can be according to the target alignment point calculated for coordinate in real space positional relationship and position in the picture
Confidence breath, determines the coordinate conversion matrix between imaging device, and the apparatus structure is simple, it is easy to accomplish.
Embodiment two
Fig. 3 is the structural block diagram of calibrating coordinates system provided by Embodiment 2 of the present invention.The calibrating coordinates system with it is aforementioned
Calibrating coordinates device described in embodiment is used cooperatively, including obtains module 31 and output module 32, obtains module 31 for obtaining
Take the image of partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and the figure of each imaging device
As the location information comprising being used as the target alignment point that coordinate calculates；Output module 32 is used for the position according to target alignment point
Spatial relation between information and target alignment point, determines the coordinate conversion matrix between imaging device.Target alignment
Spatial relation between point can be determined in advance and be stored in the memory of calibrating coordinates system.
Wherein, the imaging device of the present embodiment is usually radiation imaging apparatus, such as x-ray imaging equipment, is set with imaging
It is standby to be illustrated for CT imaging device, it is to be understood that the corresponding image of CT imaging device is usually three-dimensional CT image
Or the plain film of a certain plane, and any calibration point can be determined by the plain film of two orthogonal planes of calibrating coordinates device
Spatial relation, thus image described in the present embodiment be the three-dimensional CT image or at least two of partial coordinates calibrating installation just
Hand over the plain film of plane.Wherein, the plain film of the present embodiment be instigate CT equipment only moved along z-axis acquisition calibrating coordinates device two
Image is tieed up, for example CT bulb is maintained at 0 degree of position, and therapeutic bed only obtains calibrating coordinates device along z-axis moving sweep and puts down in x-z
The image in face, CT bulb are maintained at 90 degree or 270 degree of positions, and the calibrating coordinates dress that therapeutic bed is only obtained along z-axis moving sweep
Set the image in y-z plane.For another example, for conical beam CT, plain film refers to that CT bulb is located at 0 degree of position and 90 degree (or 270
Degree) position when the calibrating coordinates device that scans x-z-plane and y-z plane image.
It is understood that arbitrary number may be implemented if the calibrating coordinates between two imaging devices may be implemented
Calibrating coordinates between the imaging device of amount, for the ease of the elaboration of technical solution, the present embodiment is to correct two imaging devices
Coordinate for be illustrated.
If imaging device has two, the output module 32 of the present embodiment includes: benchmark image determination unit 321, virtual
Calibration point determination unit 322 and coordinate conversion matrix determination unit 323, benchmark image determination unit 321 is used for will wherein one one-tenth
Picture equipment is as benchmark imaging device, using the image of the benchmark imaging device as benchmark image；Virtual calibration point determination unit
32 for the position according to the target alignment point in the spatial relation and benchmark image between stored target alignment point
Confidence breath, determines the location information for corresponding to the virtual calibration point of another imaging device in the coordinate system where benchmark image；
Coordinate conversion matrix determination unit 323 is used for according to the location information of virtual calibration point and the target alignment point of another imaging device
Location information, determine the coordinate conversion matrix between two imaging devices.
Illustratively, as shown in Fig. 2 D and Fig. 2 E, the ontology of calibrating coordinates device is column construction, and axle center is provided with mark
Know line, calibration point P1 and calibration point P2 are provided on the tag line, two imaging devices are respectively the positioning of integrated radiotherapy system
CT and guidance CT (referring to Fig. 1).The corresponding positioning CT of calibration point P1 is set, and the corresponding image of positioning CT is FBCT (fan
Beam CT) image (D referring to fig. 2), the corresponding guidance CT of calibration point P2, and the corresponding image of guidance CT is CBCT (cone
Beam CT) image (E referring to fig. 2).Using CBCT image as benchmark image, according to the real space of calibration point P1 and calibration point P2
Positional relationship determines the virtual calibration point P21 corresponding to P1 (referring to fig. 2 in E outside CBCT image in the coordinate system of CBCT image
Dotted portion), it is assumed that positioning CT relative to guidance CT coordinate conversion matrix be TCR, then position CT and guide CT coordinate
Meet: P21(x, y)=TCRP1(x,y)。
The coordinate P of P1 in preceding formula1(x, y) is it is known that the coordinate of P21 can be according to the coordinate and P2 and two coordinate of P1 of P2
Between spatial relation determine that therefore the coordinate of P1 and P21 and coordinate conversion matrix can calculate.Coordinate conversion
After matrix calculates, positions CT and guide the whole connections set up between coordinate system between CT, so as to apply
In workflows such as image guidance.For example, adjusting guidance CT centre coordinate according to coordinate conversion matrix to position CT as benchmark equipment
To the coordinate system of positioning CT.The coordinate that P1 and P21 are determined by CBCT image and FBCT image, can make identified coordinate
Precision reaches sub-pix rank, therefore is only capable of carrying out two imaging device rotation centers in x-y plane compared to the prior art thick
It slightly calibrates, the present embodiment can carry out accurate calibration to the three-dimensional coordinate of the isocenter point of two imaging devices.
It is understood that in order to improve the accuracy of the calibrating coordinates between imaging device, each imaging device can be with
Multiple calibration points are corresponded to, i.e., include multiple target alignment points calculated for coordinate in the image of each imaging device, at this point, sitting
Marking transition matrix determination unit can location information according to the corresponding virtual calibration point of each target alignment point and another imaging
The location information of the target alignment point of equipment determines the initial coordinate transition matrix between two imaging devices, and according to two imagings
Initial coordinate transition matrix between equipment determines the coordinate conversion matrix between two imaging devices.
It is understood that coordinate conversion matrix determination unit is according to the initial coordinate transition matrix between imaging device
When determining the coordinate conversion matrix between two imaging devices, the weight system of each target alignment point can be determined and stored in advance
Number, then determines two imagings according to the weight coefficient of initial coordinate transition matrix and each target alignment point between imaging device
Coordinate conversion matrix between equipment.For example, when the corresponding two target alignment points of each imaging device, each target alignment point
Weight coefficient be 0.5, that is, take the mean value of coordinate conversion matrix corresponding to two target alignment points.
For the ease of the description of technical solution, positioning CT in the present embodiment it is consistent with the guidance coordinate direction of CT (referring to
Fig. 1), but it is understood that, even if the coordinate direction of the two is inconsistent, for example the therapeutic bed of positioning CT is moved along the z-axis, and is guided
The therapeutic bed of CT is moved along y-axis, the coordinate conversion matrix based on any embodiment of that present invention also available the two.
Optionally, as shown in figure 4, the system further includes processor 201, memory 202, input unit 203 and output
Device 204；The quantity of processor 201 can be one or more in equipment, in Fig. 4 by taking a processor 201 as an example；In equipment
Processor 201, memory 202, input unit 203 and output device 204 can pass through bus or other modes connection, figure
In 4 for being connected by bus.
Memory 202 is used as a kind of computer readable storage medium, can be used for storing software program, journey can be performed in computer
Sequence and module, software program, instruction and the module that processor 201 is stored in memory 202 by operation, thereby executing
The various function application and data processing of equipment realize the function of above-mentioned calibrating coordinates system.
Memory 202 can mainly include storing program area and storage data area, wherein storing program area can store operation system
Application program needed for system, at least one function；Storage data area, which can be stored, uses created data etc. according to terminal.This
Outside, memory 202 may include high-speed random access memory, can also include nonvolatile memory, for example, at least one
Disk memory, flush memory device or other non-volatile solid state memory parts.In some instances, memory 202 can be into one
Step includes the memory remotely located relative to processor 201, these remote memories can pass through network connection to equipment.On
The example for stating network includes but is not limited to internet, intranet, local area network, mobile radio communication and combinations thereof.
Input unit 203 can be used for receiving the number or character information of input, and generate with the user setting of equipment with
And the related key signals input of function control.
Output device 204 may include that display screen etc. shows equipment, for example, the display screen of user terminal.
The technical solution of calibrating coordinates system provided in an embodiment of the present invention, including module and output module are obtained, it obtains
Module is used to obtain the image of partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and it is each at
As the image of equipment includes the location information of the target alignment point calculated as coordinate；Output module is used for according to target alignment
Spatial relation between the location information and stored target alignment point of point determines that the coordinate between imaging device turns
Change matrix.Compared to the prior art, which can quickly and easily determine the coordinate conversion matrix between imaging device.
Embodiment three
Fig. 5 is the flow chart for the coordinate calibration method that the embodiment of the present invention three provides.The embodiment of the present invention and aforementioned implementation
Calibrating coordinates system described in example is corresponding, this method comprises:
S101, the image for obtaining partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and
The image of each imaging device includes the location information of the target alignment point calculated as coordinate.
By taking integrated radiotherapy system as an example, after the completion of generally including positioning CT and CT, calibrating coordinates device being guided to put position, control
The FBCT image that position CT acquires the partial coordinates calibrating installation in its scanning range is formulated, control guidance CT acquires its scanning range
The CBCT image of interior partial coordinates calibrating installation.Due to positioning CT and the scanning range of CT is guided at least to correspond to a calibration point
Group, therefore FBCT image and CBCT image include the target alignment point that can be used as coordinate calculating, due to FBCT image and CBCT
Image is 3-D image, therefore they include the spatial positional information of target alignment point.
S102, it is closed according to the spatial position between the location information and stored target alignment point of target alignment point
System, determines the coordinate conversion matrix between imaging device.
After getting the image of calibrating coordinates device of two imaging devices shooting, it can according to the mesh in two images
Spatial relation between the location information and stored target alignment point of calibration on schedule, determines between imaging device
Coordinate conversion matrix.
Preferably, will wherein an imaging device is as benchmark imaging device, using the image of the benchmark imaging device as base
Quasi- image；According to the target alignment point in the spatial relation and benchmark image between stored target alignment point
Location information determines the position letter for corresponding to the virtual calibration point of another imaging device in the coordinate system where benchmark image
Breath；Then according to the location information of the target alignment of the location information of virtual calibration point and another imaging device point, twenty percent is determined
As the coordinate conversion matrix between the centers such as equipment.
Illustratively, as shown in Fig. 2 D and Fig. 2 E, the ontology of calibrating coordinates device is column construction, and axle center is provided with mark
Know line, calibration point P1 and calibration point P2 are provided on the tag line, two imaging devices are respectively the positioning of integrated radiotherapy system
CT and guidance CT (referring to Fig. 1).The corresponding positioning CT of calibration point P1 is set, and the corresponding image of positioning CT is FBCT (fan
Beam CT) image (D referring to fig. 2), the corresponding guidance CT of calibration point P2, and the corresponding image of guidance CT is CBCT (cone
Beam CT) image (E referring to fig. 2).Using CBCT image as benchmark image, according to the real space of calibration point P1 and calibration point P2
Positional relationship determines the virtual calibration point P21 corresponding to P1 (referring to fig. 2 in E outside CBCT image in the coordinate system of CBCT image
Dotted portion), it is assumed that positioning CT relative to guidance CT coordinate conversion matrix be TCR, then position CT and guide CT coordinate
Meet: P21(x, y)=TCRP1(x,y)。
The coordinate P of P1 in preceding formula1(x, y) is it is known that the coordinate of P21 can be according to the coordinate and P2 and two coordinate of P1 of P2
Between spatial relation determine that therefore the coordinate of P1 and P21 and coordinate conversion matrix can calculate.Coordinate conversion
After matrix calculates, positions CT and guide the whole connections set up between coordinate system between CT, so as to apply
In workflows such as image guidance.For example, adjusting guidance CT centre coordinate according to coordinate conversion matrix to position CT as benchmark equipment
To the coordinate system of positioning CT.The coordinate that P1 and P21 are determined by CBCT image and FBCT image, can make identified coordinate
Precision reaches sub-pix rank, therefore is only capable of carrying out two imaging device rotation centers in x-y plane compared to the prior art thick
It slightly calibrates, the present embodiment can carry out accurate calibration to the three-dimensional coordinate of the isocenter point of two imaging devices.
It is understood that in order to improve the accuracy of the calibrating coordinates between imaging device, each imaging device can be with
Multiple calibration points are corresponded to, i.e., include multiple target alignment points calculated for coordinate in the image of each imaging device, at this point, sitting
Marking transition matrix determination unit can location information according to the corresponding virtual calibration point of each target alignment point and another imaging
The location information of the target alignment point of equipment determines the initial coordinate transition matrix between two imaging devices, and according to two imagings
Initial coordinate transition matrix between equipment determines the coordinate conversion matrix between two imaging devices.
It is understood that can also be obtained other than the three-dimensional CT image of available coordinate transformation device by CT
The plain film of some plane of coordinate transformation device is taken, and the plain film of two normal surfaces can determine the spatial position of target alignment point
Relationship, therefore the image of the present embodiment is two orthogonal plane of three-dimensional CT image or calibrating coordinates device of calibrating coordinates device
Plain film.
Coordinate calibration method compared to the prior art, the present embodiment obtain coordinate using existing positioning CT and guidance CT
The image of calibrating installation does not need to increase additional machinery accuracy detecting device, realizes that difficulty is low, at low cost, can achieve sub- picture
The detection accuracy of plain rank higher than common mechanical detection precision, and reduces positioning CT and guides the relevant workflow of CT
Systematic error influence.
Example IV
Fig. 6 is the flow chart for the coordinate calibration method that the embodiment of the present invention four provides.Coordinate provided in an embodiment of the present invention
Calibration method is used for using calibrating coordinates device and calibrating coordinates system described in previous embodiment at least two imaging devices
Calibrating coordinates are carried out, this method comprises:
S201, pendulum position is carried out to calibrating coordinates device, make lubber-line while appears in the scanning of imaging device to be calibrated
In range, and at least corresponding target alignment point calculated for coordinate of the scanning range of each imaging device.
Using calibrating coordinates device described in previous embodiment and calibrating coordinates system at least two imaging devices into
When row calibrating coordinates, needs first to carry out pendulum position to calibrating coordinates device, make the ontology of calibrating coordinates device while being located at two imagings
In the scanning range of equipment, and make a calibration point group at least occur in the scanning range of each imaging device.Wherein, each school
Group includes at least a calibration point on schedule.
It is understood that in order to improve the accuracy of the calibrating coordinates between imaging device, each imaging device can be with
Multiple calibration points are corresponded to, i.e., include multiple target alignment points calculated for coordinate in the image of each imaging device, at this point, sitting
Marking transition matrix determination unit can location information according to the corresponding virtual calibration point of each target alignment point and another imaging
The location information of the target alignment point of equipment determines the initial coordinate transition matrix between two imaging devices, and according to two imagings
Initial coordinate transition matrix between equipment determines the coordinate conversion matrix between two imaging devices.
S202, the image for obtaining partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and
The image of each imaging device includes the location information of the target alignment point calculated as coordinate.
By taking integrated radiotherapy system as an example, imaging device is usually to position CT and guidance CT, and it is complete that calibrating coordinates device puts position
Cheng Hou, control positioning CT acquire the FBCT image of the partial coordinates calibrating installation in its scanning range, and control guidance CT acquires it
The CBCT image of partial coordinates calibrating installation in scanning range.Due to positioning CT and the scanning range of CT is guided at least to correspond to one
A calibration point group, therefore FBCT image and CBCT image include the target alignment point that can be used as coordinate calculating, since FBCT schemes
Picture and CBCT image are 3-D image, therefore they include the spatial positional information of target alignment point.
S203, according to the spatial relation between the location information and target alignment point of target alignment point, determine at
As the coordinate conversion matrix between equipment.
After getting the image of calibrating coordinates device of two imaging devices shooting, it can according to the mesh in two images
Spatial relation between the location information and stored target alignment point of calibration on schedule, determines between imaging device
Coordinate conversion matrix.
Preferably, will wherein an imaging device is as benchmark imaging device, using the image of the benchmark imaging device as base
Quasi- image；According to the target alignment point in the spatial relation and benchmark image between stored target alignment point
Location information determines the position letter for corresponding to the virtual calibration point of another imaging device in the coordinate system where benchmark image
Breath；Then according to the location information of the target alignment of the location information of virtual calibration point and another imaging device point, twenty percent is determined
As the coordinate conversion matrix between the centers such as equipment.
Illustratively, as shown in Fig. 2 D and Fig. 2 E, the ontology of calibrating coordinates device is column construction, and axle center is provided with mark
Know line, calibration point P1 and calibration point P2 are provided on the tag line, two imaging devices are respectively the positioning of integrated radiotherapy system
CT and guidance CT (referring to Fig. 1).The corresponding positioning CT of calibration point P1 is set, and the corresponding image of positioning CT is FBCT (fan
Beam CT) image (D referring to fig. 2), the corresponding guidance CT of calibration point P2, and the corresponding image of guidance CT is CBCT (cone
Beam CT) image (E referring to fig. 2).Using CBCT image as benchmark image, according to the real space of calibration point P1 and calibration point P2
Positional relationship determines the virtual calibration point P21 corresponding to P1 (referring to fig. 2 in E outside CBCT image in the coordinate system of CBCT image
Dotted portion), it is assumed that positioning CT relative to guidance CT coordinate conversion matrix be TCR, then position CT and guide CT coordinate
Meet: P21(x, y)=TCRP1(x,y)。
The coordinate P of P1 in preceding formula1(x, y) is it is known that the coordinate of P21 can be according to the coordinate and P2 and two coordinate of P1 of P2
Between spatial relation determine that therefore the coordinate of P1 and P21 and coordinate conversion matrix can calculate.Coordinate conversion
After matrix calculates, positions CT and guide the whole connections set up between coordinate system between CT, so as to apply
In workflows such as image guidance.For example, adjusting guidance CT centre coordinate according to coordinate conversion matrix to position CT as benchmark equipment
To the coordinate system of positioning CT.The coordinate that P1 and P21 are determined by CBCT image and FBCT image, can make identified coordinate
Precision reaches sub-pix rank, therefore is only capable of carrying out two imaging device rotation centers in x-y plane compared to the prior art thick
It slightly calibrates, the present embodiment can carry out accurate calibration to the three-dimensional coordinate of the isocenter point of two imaging devices.
It is understood that in order to improve the accuracy of the calibration of the isocenter point between imaging device, each imaging device
Multiple calibration points can be corresponded to, i.e., include multiple target alignment points calculated for coordinate in the image of each imaging device, this
When, coordinate conversion matrix determination unit can be according to the location information of the corresponding virtual calibration point of each target alignment point and another
The location information of the target alignment point of imaging device, determines the initial coordinate transition matrix between two imaging devices, and according to two
Initial coordinate transition matrix between imaging device determines the coordinate conversion matrix between two imaging devices.
It is understood that can also be obtained other than the three-dimensional CT image of available coordinate transformation device by CT
The plain film of some plane of coordinate transformation device is taken, and the plain film of two normal surfaces can determine the spatial position of target alignment point
Relationship, therefore the image of the present embodiment is two orthogonal plane of three-dimensional CT image or calibrating coordinates device of calibrating coordinates device
Plain film.
The pendulum position of coordinate calibration method compared to the prior art, the present embodiment calibrating coordinates device is simple, and only needs
It positions CT and CT is guided to obtain the image of calibrating coordinates device, do not need to increase additional machinery accuracy detecting device, it is difficult to realize
Spend it is low, it is at low cost, can achieve the other detection accuracy of sub-pixel, higher than common mechanical detection precision, and reduce it is fixed
The systematic error of position CT and guidance CT relevant workflow influences.
Embodiment five
The embodiment of the present invention five also provides a kind of storage medium comprising computer executable instructions, and the computer can be held
Coordinate calibration method described in previous embodiment is realized in row instruction when being executed as computer processor, this method comprises:
Obtain the image of partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and each institute
The image for stating imaging device includes the location information of the target alignment point calculated as coordinate；
According to the spatial relation between the location information and stored target alignment point of the target alignment point,
Determine the coordinate conversion matrix between the imaging device.
By the description above with respect to embodiment, it is apparent to those skilled in the art that, the present invention
It can be realized by software and required common hardware, naturally it is also possible to which by hardware realization, but in many cases, the former is more
Good embodiment.Based on this understanding, technical solution of the present invention substantially in other words contributes to the prior art
Part can be embodied in the form of software products, which can store in computer readable storage medium
In, floppy disk, read-only memory (Read-Only Memory, abbreviation ROM), random access memory (Random such as computer
Access Memory, abbreviation RAM), flash memory (FLASH), hard disk or CD etc., including some instructions are used so that a calculating
Machine equipment (can be personal computer, server or the network equipment etc.) realizes the corresponding technical effect of calibrating coordinates system.
It is worth noting that, included each unit and module are only pressed in the embodiment of above-mentioned calibrating coordinates system
It is divided, but is not limited to the above division according to function logic, as long as corresponding functions can be realized；In addition,
The specific name of each functional unit is also only for convenience of distinguishing each other, the protection scope being not intended to restrict the invention.
Note that the above is only a better embodiment of the present invention and the applied technical principle.It will be appreciated by those skilled in the art that
The invention is not limited to the specific embodiments described herein, be able to carry out for a person skilled in the art it is various it is apparent variation,
It readjusts and substitutes without departing from protection scope of the present invention.Therefore, although being carried out by above embodiments to the present invention
It is described in further detail, but the present invention is not limited to the above embodiments only, without departing from the inventive concept, also
It may include more other equivalent embodiments, and the scope of the invention is determined by the scope of the appended claims.
Claims (12)
1. a kind of calibrating coordinates device, which is characterized in that the calibration for the coordinate between at least two imaging devices, comprising:
Ontology；
The calibration point group of corresponding each imaging device, is arranged on the body, and each calibration point group includes at least right positioned at institute
A calibration point of the scanning range of imaging device is answered, and the spatial relation of the calibration point between different calibration point groups is solid
It is fixed.
2. the apparatus according to claim 1, which is characterized in that further include:
Fixed frame, the fixed frame is used to support the ontology so that the body position is fixed.
3. the apparatus according to claim 1, which is characterized in that the ontology is made of rigid material.
4. the apparatus of claim 2, which is characterized in that the ontology is fabricated from a flexible material, the flexible material
Ontology keep the spatial relation between the calibration point of different calibration point groups constant by the fixed frame.
5. device according to claim 1 to 4, which is characterized in that the calibration point that different calibration point groups are included is in line
Property distribution.
6. a kind of calibrating coordinates system, which is characterized in that based on any calibrating coordinates device of claim 1-5, comprising:
Module is obtained, for obtaining the figure of partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated
Picture, and the image of each imaging device includes the location information of the target alignment point calculated as coordinate；
Output module is closed for the spatial position between the location information and target alignment point according to the target alignment point
System, determines the coordinate conversion matrix between the imaging device.
7. system according to claim 6, which is characterized in that the imaging device to be calibrated has two, correspondingly, institute
Stating output module includes:
Benchmark image determination unit, for will wherein an imaging device is as benchmark imaging device, by the benchmark imaging device
Image is as benchmark image；
Virtual calibration point determination unit, for according to the spatial relation and the benchmark image between target alignment point
In target alignment point location information, determined in the coordinate system where the benchmark image and correspond to another imaging device
The location information of virtual calibration point；
Coordinate conversion matrix determination unit, for according to the location information of the virtual calibration point and another imaging device
The location information of target alignment point, determines the coordinate conversion matrix between two imaging devices.
8. system according to claim 7, which is characterized in that if the calibration point group of each imaging device includes at least two
A target alignment point, the coordinate conversion matrix determination unit are used for according to the corresponding virtual calibration point of each target alignment point
The location information of the target alignment point of location information and another imaging device, determines the initial coordinate between two imaging devices
Transition matrix, and determine that the coordinate between two imaging devices converts square according to the initial coordinate transition matrix between two imaging devices
Battle array.
9. according to system as claimed in claim 6 to 8, which is characterized in that described image is that CT image or two are orthogonal flat
The plain film in face.
10. a kind of coordinate calibration method, which is characterized in that make with any calibrating coordinates device cooperation of claim 1-5
With, comprising:
Obtain the image of partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and it is each it is described at
As the image of equipment includes the location information of the target alignment point calculated as coordinate；
According to the spatial relation between the location information and target alignment point of the target alignment point, the imaging is determined
Coordinate conversion matrix between equipment.
11. a kind of coordinate calibration method, which is characterized in that make with any calibrating coordinates device cooperation of claim 1-5
With, comprising:
Pendulum position is carried out to calibrating coordinates device, make the lubber-line while appearing in the scanning range of imaging device to be calibrated
It is interior, and at least corresponding target alignment point calculated for coordinate of the scanning range of each imaging device；
Obtain the image of partial coordinates calibrating installation corresponding to the scanning range of imaging device to be calibrated, and it is each it is described at
As the image of equipment includes the location information of the target alignment point calculated as coordinate；
According to the spatial relation between the location information and target alignment point of the target alignment point, the imaging is determined
Coordinate conversion matrix between equipment.
12. a kind of storage medium comprising computer executable instructions, which is characterized in that the computer executable instructions by
For realizing coordinate calibration method as claimed in claim 10 when computer processor executes.
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